HasMetrics

Calculates metrics on ActiveRecord entries and caches them so they can be queried from a database. The calculated values are stored in another table which gets automatically created and migrated as needed.

Installation

Add this line to your application's Gemfile:

gem 'has_metrics'

And then execute:

$ bundle

Or install it yourself as:

$ gem install has_metrics

Usage

# Memoize in DB for 24 hours as an integer
has_metric :total_offer_count do
  activities.by_action(:offer).count
end

# Memoize in DB for 1 hour as an integer
has_metric :total_share_count, :every => 1.hour do
  activities.by_action(:share).count
end

# Memoize in DB for 24 hours as a float
has_metric :average_shares_per_offer, :type => :float do
  total_share_count.to_f / total_offer_count
end

TODO

1. Tests
2. Refactoring
3. Better readme
4. Extract related functionality into gem
   • segments - lets you use has_metrics to segment all records in a table between some set of string values
   • has_custom_order_by - provides default names scopes for sorting based on metrics & segments by joining the metrics table

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request